The attacks were the latest in a relentless push by Sunni militants to undermine confidence in the Shiite-led government's efforts to maintain security in Iraq, two years after the pullout of American troops from the country.

There was no immediate claim of responsibility for the bombings but such systematic and brazen attacks against government buildings, security forces and Shiites in general bear the hallmarks of al-Qaida's affiliate in Iraq. The terror group has become emboldened by the successes of its fellow militants in the civil war next door in Syria and by widespread Sunni anger at the government in Baghdad.

The deadliest of Wednesday's attacks took place across the street from the Foreign Ministry building, when two parked car bombs went off simultaneously in two different parking lots. Those explosions killed at least 12 people, including three policemen, and wounded 22, a police officer said.

Shortly afterward, a suicide bomber walked into a nearby falafel restaurant where he set off his explosives-laden belt, killing five people and wounding 12, the officer added. The restaurant and others around it are often used by officials or visitors waiting for security escorts to take them inside the Green Zone.

Also Wednesday morning, a parked car bomb went off in Khilani Square in the Iraqi capital's commercial center, killing five people and wounding 11, another police officer said. Security forces sealed off the area as firefighters struggled to put out the blaze ignited by the bombing. Smoke billowed from several stores and stalls as some vendors hurriedly stuffed their goods into big bags and carried them away on their backs.

Two medical officials confirmed the causality figures. All officials spoke on condition of anonymity as they were not authorized to talk to media.

Iraq has seen resurgence in violence over the past year. According to UN figures, 2013 had the highest death toll since the worst of the country's sectarian bloodletting began to subside in 2007. The UN said violence killed 8868 last year.

Al-Qaida's affiliate in Iraq has in the past staged spectacular attacks on Iraqi government ministries such as in August 2009, when suicide bombers hit the Finance Ministry and the Foreign Ministry ministries, killing more than 100 people. The bombings were quickly claimed by the Islamic State of Iraq, as the group was known at the time.